Funny you should say that.
As I click on this site via the favourits it will open (this site) and then go straight to a blank screen as if being re-directed, so I go back a step and re-click and all is well ? (only this site)

I also got this a couple of days ago on my iPad , definitely nothing based on tracking cookies as I don't look up porn on my iPad.

Could it be from another site though, I don't think you necesarily have to have visited a porn site to get this stuff, try deleting out all cookies etc or try private browsing and see if it still happens.